One of two former top strategists for the Trump campaign is “likely” to face indictment as early as Monday, a senior Democrat said Sunday, previewing what would be the first criminal charges in the intensifying probe led by special counsel Robert S. Mueller III into current and former members of President Trump’s inner orbit.

Rep. Adam B. Schiff (D-Burbank), ranking member of the House Intelligence Committee, said a federal judge could unseal an indictment against either Paul Manafort, Trump’s former campaign manager, or Michael Flynn, who briefly served as Trump’s national security advisor in the White House.

Schiff’s comments came amid intense speculation at the White House and on Capitol Hill over media reports that a federal grand jury in Washington has approved its first indictment in the FBI investigation into Russian meddling in the 2016 election and whether members of Trump’s campaign actively colluded with Moscow.

Schiff, a former federal prosecutor in Los Angeles, said he was reacting to press reports and could not confirm the target or whether it involved Russia. “We haven’t been told who it is,” he said on ABC’s “This Week.”

Representatives of Flynn and Manafort could not be reached for comment on Sunday, and some reports suggested other individuals might be the focus of the sealed indictment.

Trump did not specifically react to the expected indictment, but in an angry series of tweets, he denounced what he called “phony Trump/Russia… ‘collusion,’ which doesn’t exist.”

As in the past, he sought to blame partisan politics for the widening scandal, accusing rival Hillary Clinton and Democrats of orchestrating the FBI investigations, the grand jury probe and multiple congressional inquiries in an effort to undermine his administration.

“The Dems are using this terrible (and bad for our country) Witch Hunt for evil politics, but the R’s…are now fighting back like never before. There is so much GUILT by Democrats/Clinton, and now the facts are pouring out. DO SOMETHING!”

He added, “All of this ‘Russia’ talk right when the Republicans are making their big push for historic Tax Cuts & Reform. Is this coincidental? NOT!”

Manafort, a political consultant, has long been active in Republican circles in Washington even as he developed major business deals in Russia and Ukraine. Manafort was paid tens of millions of dollars for his work on behalf of the former Russian-backed government in Ukraine.

He has been a target of an FBI counterintelligence investigation since at least 2014, two years before he joined Trump’s campaign, although he was never charged.

In 2014, federal authorities obtained a special warrant from the Foreign Intelligence Surveillance Court to secretly eavesdrop on Manafort’s communications. The warrant was renewed in early 2016 before lapsing last October, according to lawyers familiar with the matter.

This summer, on July 26, a team of FBI agents armed with a “no knock” warrant raided Manafort’s residence in Alexandria, Va., to collect digital records and other evidence. In August, the New York Times reported that federal prosecutors had informed Manafort’s lawyers of their intention to secure his indictment.

Flynn, a retired Army three-star general and former head of the Defense Intelligence Agency, served as a senior national security advisor to Trump during the campaign and spoke on his behalf at the Republican National Convention.

He was named national security advisor after Trump won the election but resigned after just 24 days following news reports of his telephone and personal contacts with Russia’s ambassador to Washington. Flynn subsequently amended personal-financial disclosure forms to report previously unacknowledged income from foreign clients.

The expected indictment — and whether it focuses on criminal activity during the 2016 presidential race or from business dealings prior to or separate from the campaign — dominated Sunday TV talk shows.

“It’s going to be really important whether or not this indictment involves 15-year-old business transactions or 15-day-old conversations with Russia,” Rep. Trey Gowdy, (R-S.C.), chairman of the House Oversight and Government Reform Committee, said on Fox News Sunday.

Gowdy, a former federal prosecutor, decried the apparent leak of a sealed grand jury indictment, which he said was illegal. But he declined to impugn Mueller’s leadership of the investigation and said he saw no grounds for Mueller to resign.

“I readily concede I’m in an increasingly small group of Republicans,” Gowdy said. “I think Bob Mueller has a really distinguished career of service to our country.… I would encourage my Republican friends: Give the guy a chance to do his job.”

Sen. Susan Collins, (R-Maine), a member of the Senate Intelligence Committee, one of four congressional panels conducting investigations separate from Mueller’s criminal probe, was asked on CBS’s “Face the Nation’’ about any sign of collusion between Russia and the Trump campaign.

“I have not yet seen any definitive evidence of collusion,” Collins responded. “I have seen lots of evidence that the Russians were very active in trying to influence the election.”

U.S. intelligence agencies have concluded that the Russian government purposefully sought to meddle in the U.S. election, notably through hacking of Democratic Party emails and targeted postings on social media sites, to discredit American democracy and to help Trump beat Clinton.

Trump has consistently denied any improper ties to Russia, and has said he is not a target of the FBI investigation.